[PATCH 5/8] spi: stm32: defer probe for reset

[Alain Volmat <alain.volmat@foss.st.com>]

Defer the probe operation when a reset controller device is expected
but have not yet been probed.

This change replaces use of devm_reset_control_get_exclusive() with
devm_reset_control_get_optional_exclusive() as reset controller is
optional which is now explicitly stated.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
---
 drivers/spi/spi-stm32.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 22bd3d1c8d69..c40cea0640e6 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1891,8 +1891,14 @@ static int stm32_spi_probe(struct platform_device *pdev)
 		goto err_clk_disable;
 	}
 
-	rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
-	if (!IS_ERR(rst)) {
+	rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+	if (rst) {
+		if (IS_ERR(rst)) {
+			ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
+					    "failed to get reset\n");
+			goto err_clk_disable;
+		}
+
 		reset_control_assert(rst);
 		udelay(2);
 		reset_control_deassert(rst);
-- 
2.17.1